Modeling means that a model is created from an article/structure under design for describing the article/structure to be constructed, the model containing at least information needed to illustrate the article/structure. The development of data processing systems and computers has transformed modeling into a computerized process, where a product model is created from the article/structure. For example, the product model of a building is an entity consisting of the product data on the life span of the building and building process.
Computer applications typically apply predefined object types that are provided with values in connection with the modeling to create model objects of articles that exist or will exist in the real world. Examples of these object types in the field of building modeling include beams, columns, plates and reinforcement. The object types map to precast structures that are unambiguous and distinct units. However, mapping the object types to cast-in-place structures is not so simple; the cast-in-place structures cannot be divided into structural building elements since there are no exact definitions when a slab ends and a beam supporting the slab starts, for example.